We give simple algorithms for the construction of generator matrices for minimal tail-biting trellises for a powerful and practical subclass of the linear cyclic codes, from which the combinatorial representation in the form of a graph can be obtained by standard procedures.

For a prime number p, we construct a generating set for the ring of invariants for the p+1 dimensional indecomposable modular representation of a cyclic group of order p. We then use the constructed invariants to describe the decomposition of the symmetric algebra as a module over the group ring, confirming the Periodicity Conjecture of Ian Hughes and Gregor Kemper for this case.

For certain cyclic cubic fields k, we verified that Iwasawa invariants λ3(k) vanished by calculating units of abelian number field of degree 27. Our method is based on the explicit representation of a system of cyclotomic units of those fields.

In this note, we prove that the projective normality of (P(V )/G,L), the celebrated theorem of Erdös-Ginzburg-Ziv and normality of an affine semigroup are all equivalent, where V is a finite dimensional representation of a finite cyclic group G over C and L is the descent of the line bundle O(1)⊗|G|.

The intersection cohomologies of closures of nilpotent orbits of linear (respectively, cyclic) quivers are known to be described by KazhdanLusztig polynomials for the symmetric group (respectively, the affine symmetric group). We explain how to simplify this description using a combinatorial cancellation procedure, and we derive some consequences for representation theory.

For two covariant differential ∗-calculi, the twisted cyclic cocycle associated with the volume form is represented in terms of commutators [F , ρ(x)] for some self-adjoint operator F and some ∗-representation ρ of the underlying ∗-algebra. MSC (2000): 17B37; 46L87; 81R50

The (reduced) Burau representation Vn of the braid group Bn is obtained from the action of Bn on the homology of an infinite cyclic cover of the disc with n punctures. In this paper, we calculate H∗(Bn;Vn). As an application, we show that the expected number of Fq-points on a random superelliptic curve is equal to q.

Let Cp denote the cyclic group of order p where p ≥ 3 is prime. We denote by Vn the indecomposable n dimensional representation of Cp over a field F of characteristic p. We compute a set of generators, in fact a SAGBI basis, for the ring of invariants F[V2 ⊕ V2 ⊕ V3]p .

For certain cyclic cubic fields k, we verified that Iwasawa invariants λ3(k) vanished by calculating units of abelian number field of degree 27. Our method is based on the explicit representation of a system of cyclotomic units of those fields.

We determine the trace function representation, or equivalently, the Fourier spectral sequences of binary Jacobi sequences of period pq, where p and q are two distinct odd primes. This includes the twin-prime sequences of period p(p + 2) whenever both p and p + 2 are primes, corresponding to cyclic Hadamard difference sets. c © 2008 Elsevier B.V. All rights reserved.